1. Field of Invention
The present invention relates to an interactive information distribution system. More particularly, the invention relates to a method and apparatus for improving sharing of the processing loads and increasing the fault tolerance at each of a plurality of head-ends in an information distribution system.
2. Description of the Background Art
Video distribution systems typically utilize a plurality of cable head-ends. A head-end serves as a distribution point for a designated “neighborhood” of subscribers. Subscriber requests for video information, such as movies, are made by a subscriber using a remote control device to select from a menu of available titles displayed on a display device. After selection by a subscriber, a request for the selected video information is sent to the local head-end supporting the subscriber. The requested video information is then transmitted from the head-end to the subscriber for viewing. A typical head-end comprises a video server system that contains subsystems for managing, storing and distributing the video content.
In a system comprising a large number of subscribers, each head-end experiences a high level of activity. This typically results in delays in responding to subscriber requests. In addition, data processing and/or transmission errors increase as the demand placed upon the head-end increases. For example, physical hardware errors, such as those caused by thermal stresses created during component over-utilization, may result in unacceptable viewing experiences for the subscriber.
Therefore, there is a need in the art for more robust head-end functionality within an information distribution system by distributing head-end processing functions among a plurality of processing elements in a manner that provides increased fault tolerance and, ideally, reduced system latency.